### Motions of the Earth - Worksheets

CBSE Worksheet 01

Ch-14 Motions of the Earth

1. Which of the following statement is false regarding why only one half of the earth gets light at one time?
1. The earth receives light from the sun
2. Portion receive light experience day
3. the other half away from the sun experiences day
4. Due to the spherical shape of the earth
2. On ________, the Northern Hemisphere is tilted towards the sun.
1. 21st June
2. 21st January
3. 28th February
4. 23rd March
3. The time of the day just before sunrise is known as:
1. Dawn
2. Noon
3. Dusk
4. Morning
4. How much time does the earth take time to complete its rotation?
1. 22
2. 23
3. 24
4. 20
5. ________ is the diffused light before sunrise, while ________ is the diffused light after sunset.
1. Morning, Night
2. Dawn, Twilight
3. Dawn, Morning
4. Morning, Noon
6. Match the following:
 Column A Column B (i) Winter Solstice (a) Earth day (ii) Summer Solstice (b) 21st March (iii) Equinox (c) 21st June (iv) Period of Rotation (d) 22nd December
7. Fill in the blanks:
1. The axis of the Earth is an _________ line.
2. The earth travels around the sun in ________ orbit.
3. The earth rotates from ________.
4. The earth takes about ________ to complete one rotation around its axis.
8. State true or false:
1. On 21st March, it is the autumn season in the Northern Hemisphere and spring season in the Southern Hemisphere.
2. The sun goes around the earth in an elliptical orbit.
3. On 21st March and 23rd September the whole earth experiences equal days and nights.
4. The axis of the earth makes an angle of $23\frac{1}{2}$ with its orbital plane.
9. What is Earthday?
10. On which day the direct rays of the sun fall on the equator?
11. Why do the poles experience about six months of day and night?
12. What is a leap year?
13. Why does the Southern Hemisphere experience Winter and Summer Solstice at different times than that of the Northern Hemisphere?
14. How does the earth’s revolution take place? Explain how are seasons caused?

CBSE Worksheet 01
Ch-14 Motions of the Earth

Solution

1. (c) the other half away from the sun experiences day
Explanation: The earth receives light from the sun. Due to the spherical shape of the earth, only half of it gets light from the sun at a time. The portion facing the sun experiences day while the other half away from the sun experiences night.
2. (a) 21st June
Explanation: On 21st June, the Northern Hemisphere is tilted towards the sun. The rays of the sun fall directly on the Tropic of Cancer.
3. (a) Dawn
Explanation: The first appearance of light in the sky before sunrise.
4. (c) 24
Explanation: The earth takes about 24 hours to complete one rotation around its axis. The period of rotation is known as the Earthday. This is the daily motion of the earth.
5. (b) Dawn, Twilight
Explanation: Dawn is the first appearance of light in the sky before sunrise.
Twilight is the time between day and night when there is light outside, diffused light after sunset.
6. (i) - (d), (ii) - (c), (iii) - (b), (iv) - (a).
1. Imaginary
2. Elliptical
3. West to east
4. 24 hours
1. False. On 23rd September, it is autumn season in the Northern Hemisphere and spring season in the Southern Hemisphere.
2. True
3. True
4. False. The angle of inclination of the earth’s axis with its orbital plane is 66½°.
7. The earth takes about 24 hours to complete one rotation around its axis. The period of rotation is known as the Earthday. This is the daily motion of the earth.
8. On 21st March and September 23rd, direct rays of the sun fall on the equator.
9. The Poles experience about six months of day and six months of the night because of the tilt of the Earth on its axis. When the North Pole is tilted towards the Sun, it experiences continuous daylight for six months and when the South Pole is away from the sun, it experiences continuous darkness for six months.
10. The earth rotates around the sun for 365 days and 6 hours. For our convenience, we count only 365 days. So after every 4 years, when 24 hours get completed we add the time as the additional day in February which is of 29 days. Thus, every fourth year is known as a leap year.
11. The Earth is always revolving and it is divided into two hemispheres. The part of the earth which faces the sun experiences summer and the part away from the sun experiences winter. Therefore, Southern Hemisphere experience Winter and Summer Solstice at different times than that of the Northern Hemisphere.
12. Revolution is the movement of the earth around the sun in a fixed path or orbit. The time of revolution is 365 days 6 hours. The change of season takes place the revolution of the Earth. The Earth revolves around the Sun on an elliptical orbit. Its axis is inclined in the same direction (east) on its orbit. The revolution of the Earth and the inclination of the earth’s axis in a fixed direction cause season. A year is divided into four seasons. They are Spring, Summer, Autumn and Winter. Seasons change with the change in the position of the Earth around the Sun.